MATHEMATIC 250-Assume that random guesses are made for 10 multiple
Question:
17. Assume that random guesses are made for 10 multiple choice questions on an ACT test and that there are 5 choices for each question with probability of success 0.35. Find the probability that the number of correct answers is at most 4 (This problem meets all the requirements of a binomial situation.)
A. 0.514
B. 0.751
C. 0.942
D. 0.579
5. A researcher obtains data by examining police records for the last ten years on violent crimes during Spring Breaks. Identify the types of study for this description.
A. Observational and Retrospective
B. Observational and Prospective
C. Experimental and Cross-sectional
D. Experimental and Retrospective
12. If P (A) - 0.07, which one of the following statements is false? | |
B. The probability of event A happening twice in a row (with replacement) is 0.0049. | |
C. A is not an "unusual" event | |
D. A is not a certain event. |
15. One card is randomly chosen from a standard deck of 52 cards.If the cards are drawn without replacement, what is the probability that one King and an Ace card are chosen in either order?
| A. ( 4/52 - 4/51) B. 2(4/52 - 4/51) C. 2(4/52 + 4/51) D. (4/52 + 4/51) |
17. Assume that random guesses are made for 10 multiple choice questions on an ACT test and that there are 5 choices for each question with probability of success 0.35. Find the probability that the number of correct answers is at most 4 (This problem meets all the requirements of a binomial situation.)
A. 0.514
B. 0.751
C. 0.942
D. 0.579
22. The heights of adult males are normally distributed with a mean of 75 inches and a standard deviation of 3.5 inches.
A. 15% B. 38% C. 19% D. 12%
23. Suppose random samples of 16 male heights are selected repeatedly from the population. What is the mean and standard deviation for the sampling distribution of sample means? A. Mean = 75, SD = 3.5 B. Mean = 72, SD = 4 C. Mean = 72, SD = 16 D. Mean = 75, SD = 0.875 |
| 24. What is the probability of randomly selecting 16 males whose average height is at most 72 inches? | |||
| A. 0.0003 | B. 0.9995 | C. 0.8043 | D. 0.1957 |
Problems 25 - 27 refer to the following situation:
25. Compute a 95% confidence interval for the mean home run percentage, given that the sample standard deviation was s= 5.21
A. 7.64 ± 1.48 B. 7.64 ± 2.17 C. 7.64 ± 4.17 D. 7.64 ± 2.09
26. Assume the population standard deviation is estimated to be ? = 5.61
How large a sample, n, should be used to obtain a margin of error of 2 with 95% confidence?
A. 31 B. 45 C. 205 D. 257
27. Consider the situation given in Problem #26. Which of the following would produce a confidence interval with a smaller margin of error?
A. Using a confidence level of 90%
B. Using a smaller estimate for ?
C. Using a larger sample size
D. All of the above A-C )
34. The National Institute on Alcohol Abuse and Alcoholism reported that 45.6% of eighth-graders had used alcohol. A random sample of 100 eighth-graders showed that 41 of them had used alcohol. Is there evidence that the population proportion of eighth-graders has changed? Use ? = 0.05 Compute the P value for this test.
A. 0.5440 B. 0.3557 C. 0.1779 D. 0.4100
35. Suppose for a particular hypothesis test, a = 0.04 and the P value = 0.05. Which of the following statements is TRUE?
A. We reject the null hypothesis.
B. We fail to reject the null hypothesis.
C. The observed result is “unusual”.
D. The computed test statistic, z, does fall in the shaded critical region of the tail in the normal curve.
37. A correlation coefficient of 0.057 between two quantitative variables A and B indicates that A. As A increases, B tends to increase. B. Changes in A cause changes in B. C. As A increases, B tends to decrease. D. There is a very weak association between A and B, and change in A will not affect B. |
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Solution: MATHEMATIC 250-Assume that random guesses are made for 10 multiple